1. Field of the Invention
This invention relates generally to a cutting and mowing apparatus. In particular, this invention relates to an apparatus for translating a continuous chain of cutting blades around the perimeter of an elongated frame member. The apparatus may be conveniently powered by the hydraulic system of an existing tractor or combine, or by an independent electric or gasoline motor.
2. Description of Related Technology
Conventional cutting and mowing apparatus typically utilize a number of reciprocating knife edged blades in conjunction with periodically spaced center guards. The disadvantage of reciprocating blade technology is well-known. For instance, this type of cutter causes plants being harvested to be bent forwardly and sidewardly during blade reversals, thereby compressing the plants between the center guards prior to the cutting action. Even if damage to the plants being cut is not a consideration, the use of a reciprocating cutting action creates considerable vibration as the blades reverse direction throughout the cutting cycle. The reciprocating action of the blades tends to create more noise, and is slowed by the fact that the sickle or blade must stop at each end of the cutting stroke in order to reverse direction.
Numerous devices have been utilized in an effort to avoid, or at least minimize, the disadvantages of a reciprocating cutting device. For example, U.S. Pat. No. 391,142, issued to Gumz, discloses a rotary cutting device. The use of sprocket wheels D and R permits a series of knife blades A to be continuously translated between center fingers F. In this particular system, the chain formed by knife blades A must be kept in continuous tension in order to prevent slippage between chain links H.
U.S. Pat. No. 395,493, issued to Hanson, discloses a cutting mechanism utilizing a continuous chain. In order to reduce the requirement for constant tension in the chain, a conventional chain is used to engage sprocket wheels, while cutting blades E' are periodically fastened to the chain. A requirement of this system is the preservation of a considerable space between successive blades in order to accomplish the desired rotation and engagement functions as the blades pass over the sprocket wheel.
U.S. Pat. No. 468,859, issued to Wright, discloses a rotary sickle. The blades D2 are attached to an existing chain which travels along a path D1, thereby preventing any twisting movement of the chain itself or the blades that are attached to it. Again, a considerable space must be left between succeeding blades in order to allow for proper travel of the chain along the sprocket wheels.
U.S. Pat. No. 589,611, issued to Northern, discloses a mowing and reaping machine. Succeeding blades 25 are attached my means of clasp 30, thereby forming a continuous chain made up of alternating links of clasps 30 and blades 25. Successive blades 25 are thereby separated by the relatively short distance defined by the length of clasp 30. The clasp and the rear extension of the blade 25 are retained in a channel 13 in order to give the entire chain additional stability as it passes between fingers 12.
U.S. Pat. No. 677,095, issued to Nagel, discloses a mowing machine. The successive cutting blades 48 are connected by means of links 58. The blades 48 are actually held in place by means of semi-circular notches 61, which abut link bolts 49, thereby allowing the cutting blades to be removed from the chain without means of rivets, bolts or screws.
U.S. Pat. No. 1,200,520, issued to Platt, discloses an endless conveyor belt type of sickle. Platt discloses a separate chain 20 upon which are mounted blades. The sprocket wheel 29 engages a recessed space within the chain to advance the blades along their cutting path.
U.S. Pat. No. 1,409,507, issued to Wilson, discloses a continuous chain cutting device. Blades 16 are attached to a conventional sprocket chain 15, the entire assembly being supported in a horizontal position by means of bar 17.
U.S. Pat. No. 3,029,584, issued to Johnson, discloses an endless cutting assembly. A chain is formed by alternating links 38 with blades 39, the links being engaged by small protrusions 33 on a conventional sprocket wheel 29.
U.S. Pat. No. 3,681,901, issued to Quick et al., discloses a cutting knife assembly which may be attached to a combine. This assembly combines two rotary chains 24 and 26 traveling in opposite directions. The cutting knife assembly causes the bottom of stems of plants being cut to be displaced in the same direction as the knife travel so that after severance, the stem is inclined toward the center of the header or in the same direction as the auger feed.
U.S. Pat. No. 4,070,810, issued to Brakke, discloses a cutting apparatus. The cutting assembly consists of an endless chain carrying a plurality of cutting knives. The chain is driven by a hydraulic motor connected to a hydraulic fluid pressure system, thereby permitting the operator to control the speed of the chain as well as the direction of movement of the chain.
Each of the devices of the prior art, while sometimes satisfactory for their intended purposes, leaves something to be desired in that they are relatively complex in design, costly, cumbersome to use, and somewhat inefficient. In particular, the method of attaching the blade to the endless chain and providing for a light weight, simple, and mechanically straight forward method of transporting the blade through thousands of revolutions without jamming or the need for critical adjustment is a problem only partially addressed by the prior art devices. None of the devices disclosed has been commercially exploited or produced in quantity for use by the public.